Hospitals currently inventory a large variety of medical cover sheets for use in conventional surgery and other invasive medical procedures. While this invention has particular application for surgical procedures and is described in that context it may be used in medical procedures generally. The cover sheet or cover sheet assembly used for a procedure is dictated by the location and size of the contemplated incision. That is, the sheet or assembly has a fenestration (an opening with or without an adhesive surrounding the opening) or an incise patch (a film with or without adhesive and liner in which the adhesive may incorporate an antimicrobial agent), positioned to permit access to the contemplated surgical site with draping material surrounding the surgical zone to cover the remainder of the patient's body sufficiently to protect the surgical site from contamination by the patient's body or from the surrounding environment. Other cover sheets or cover sheet assemblies have stretchy apertures which are thermoplastic elastomeric films with an opening in the film. These drapes with stretchy apertures are particularly useful for procedures performed on limbs. In use the arm or leg is inserted through the opening of the stretchy aperture while the draping material covers the patient's body and an extremity drape is applied to the limb.
As used throughout the specification and claims the term "surgical zone" will refer to that portion of a medical cover sheet through which the patient's body is accessed for a medical or surgical procedure including fenestations, incise patches, stretchy apertures and composites made with a fenestration having a film (with or without adhesive) covering all or part of the fenestration.
Today, hospitals stock a variety of cover sheets each having the surgical zone placed at a different position in the sheet. Thus a hospital inventory would include cover sheets with the surgical zone placed near one end for head surgery, placed somewhat removed from one end for chest surgery, placed near the center of the drape for laparotomies as well as drapes with surgical zones positioned farther from the head end of the drape for knee and foot/ankle surgeries.
In addition to stocking a variety of procedure cover sheets having the surgical zone positioned in different portions of the sheet, hospitals typically inventory multiple sizes of smaller sheets which are combined to build a procedure drape assembly having a surgical zone around the surgical site. Additionally, some hospitals stock split sheets or U-shaped sheets two of which can be placed with the split or "U" openings overlapping or abutting to customize location and size of the surgical zone.
Cover sheets which can be used for multiple incision sites have been proposed. U.S. Pat. No. 4,336,797 describes a surgical cover sheet having a main sheet with a fenestration and a frame sheet with a similar fenestration secured to the upper surface of the main sheet. The frame sheet is slidably secured to the main sheet so that moving the frame sheet relative to the main sheet will vary the size and position of the surgical zone. U.S. Pat. No. 3,799,161 describes a surgical cover sheet having a plurality of fenestrations located in the sheet. Each fenestration is covered with a removably secured cover sheet so that the cover sheet positioned over the incision site can be removed while the cover sheets over the remaining fenestrations can be left in place to maintain a sterile barrier during the procedure. Great Britain Pat. No. 1,395,389 discloses a surgical cover sheet having fan folds from at least one longitudinal end to center wherein the first and second folds are smaller than the remaining folds and the second fold is a reverse fold while the third fold is a forward fold. The specification discloses that the sheet may be cut through stacks of folds to create a slit of varying lengths in the longitudinal direction. Additionally, the patent discloses creating a fenestration by making an arcuate cut in a fold of the sheet.
Another concept for providing a surgical cover sheet having utility in more than one type of surgical procedure is shown in U.S. Pat. No. 4,024,862. That patent shows a surgical cover sheet having a fenestration of sufficient size for performing an enlarged surgical procedure. Removably secured to the cover sheet on its upper surface is a flexible frame sheet having a fenestration of a smaller size than the fenestration in the main cover sheet.
Surgical cover sheets used for extremity (leg and arm) surgery frequently are constructed tubularly in the transverse direction with one longitudinal end closed. U.S. Pat. No. 4,308,864 shows a combination of conventional stockinette cover sheet and a closed tubular cover sheet. U.S. Pat. No. 3,989,040 shows a cover sheet which is tubular in the transverse direction and sealed at one longitudinal end. The cover sheet has a fenestration cut as a split in the longitudinal direction from the open end of the tube. The cover sheet has a pressure sensitive adhesive along the edges of the split for securing the sides of the fenestration relative to the surgery site.
Methods of folding cover sheets for convenient and aseptic unfolding and placement are multitudinous. Many cover sheets are folded first along transverse fold lines to reduce the longitudinal dimension of the cover sheet and thereafter along longitudinal fold lines to reduce the transverse dimension. Other cover sheets are folded first along longitudinal fold lines and thereafter along transverse fold lines. U.S. Pat. No. 4,051,865 shows a fold pattern of this latter type.